The present disclosure relates to an image forming apparatus and a method of forming an image.
When an image is formed on a sheet based on image data of an image of an original document having punch holes, the sheet on which the image has been formed (hereinafter, referred to as a copy) may include black circle images depicting the punch holes (hereinafter, may be referred to as punch hole images). In the case where such a copy is punched, it is desirable to punch holes at positions of the black circle images printed in the copy. However, it is difficult to punch holes accurately at the positions of the black circle images. If holes are punched at positions offset from the positions of the black circle images, the readability of the copy may be reduced. Furthermore, the punch holes may take away much information from the copy. Various techniques have been proposed in order to solve such a problem.
For example, some image forming apparatuses such as multifunction peripherals, copiers, and printers are capable of adding a reference mark to an image of an original document and printing the image including the reference mark on a sheet as a copy. The reference mark is used when a user punches holes in the copy. More specifically, the user performs punching with the reference mark aligned with a centering indicator of a punch. Thus, two holes are punched at desired positions in the copy. The centering indicator indicates a midpoint between two boring fixtures of the punch.
In some image forming apparatuses, a printing position of a reference mark in a copy can be set by a user's operation through an operation section. The reference mark and punch holes can be thereby prevented from overlapping a printed image of an original document in the copy.